DE2542803A1 - COMBUSTION ENGINE WITH LYING CYLINDERS AND PISTONS FOR SUCH ENGINES - Google Patents

Description

Patent μ

8 Munich 30, fcUtlsbaBe 22

SOCIETE ANONYME AUTOMOBILES CITROEN

"according to articles 118 to 150 of the French

Laws ?; through the trading companies

(societes commerciales) "

117 a 167, Ouai Andre Citroen, 757 ^ 7 tariff? Cedex 15

France

Internal combustion engine with horizontal cylinders, and pistons for such Engines.

The invention relates to the internal combustion engines a reciprocating movement executing piston with at least one piston, which in a cylinder with about horizontal axis slides, one end of which is designed as a combustion chamber, while its other end in a housing for Receiving an atmosphere lubricating the engine opens, the piston being provided with at least two circumferential grooves, each with a piston ring with an approximately rectangular cross-section is provided so that annular spaces on both sides of each piston ring arise between the piston and the cylinder, with the circumferential groove furthest from the combustion chamber with an oil control ring is provided and openings in its base has to communicate with an internal volume of the piston to set, which in turn is connected to the housing.

Such internal combustion engines, in which the axes of the cylinders are approximately horizontal, are generally

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NEN referred to as "horizontal motors".

The invention is particularly concerned with, however not exclusively, internal combustion engines with cylinders whose cylindrical peripheral wall is completely closed, and which work in four beats.

It has been found that in such horizontal engines, when the engine is started, often at the exhaust of the same a cloud of smoke arises, which is larger than that which occurs in engines whose cylinders are arranged differently are.

The invention aims in particular to train such internal combustion engines so that they are better than before correspond to the various requirements of practice and in particular no longer or to a lesser extent the above disadvantage Have dimensions.

Such an internal combustion engine is according to the invention characterized in that it has first passage means for each groove different from the groove provided with the oil control ring with a small cross-section to establish a permanent connection between the bottom of the groove and both sides of the one under consideration Groove associated piston ring lying annular spaces, and for the groove provided with the oil control ring second passage means has a small cross-section, which the bottom of this groove at least with that in relation to the oil control ring located on the side of the combustion chamber annulus in communication, said first and second passage means also higher than the lower zone of the cylinder, in which liquid lubricant can collect when the engine is not running.

The first passage means expediently comprise at least one for each groove and on each transverse surface thereof an incision which is made on the outer surface of the piston opens out and extends in sighting at the bottom of the groove over a height which is at least equal to the insertion height of the ring is in the groove, while the second passage means provided for the groove provided with the oil control ring is at least comprise an incision on the transverse surface of the groove on the side of the combustion chamber.

In the case of the first passage means, the incision provided in a transverse surface of a groove is preferably opposite.

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arranged over the incision of the other transverse surface of the groove.

Each incision preferably has a cross section in the form of a segment of a circle. The circle sections of two mutually opposite incisions are expediently inscribed in the same circumference. The largest dimension the incision in the axis of the cylinder is at most 0.2 mm

The invention also relates to a piston for internal combustion engines with at least two circumferential grooves with approximately Rectangular cross-section, with the groove furthest away from the head of the piston having openings in its base, which put them in communication with an internal volume of the piston, this piston being characterized in that it is of the groove remote from the head of the piston at least on its transverse surface closest to the piston head with at least a notch is provided, the cross section of which has in particular the shape of a segment of a circle, while the other or the other grooves closer to the piston head on each their transverse surface have at least one incision, the cross section of which in particular through a segment of a circle is formed.

The grooves of the piston have a significant circumferential zone, which is in particular greater than 180 °, on their transverse surfaces no incision whatsoever.

The invention is explained below by way of example with reference to the drawing.

Fig. 1 shows a schematic sectional view of a cylinder and a piston of an inventive Engine, the piston being cut along the line I-I of FIG is.

FIG. 2 is a top plan view of that shown in FIG. 1 Piston with removal of the piston rings.

In Fig. 1 you can partially see an internal combustion engine with a reciprocating motion Pistons. The engine includes at least one piston 1 sliding with a reciprocating motion in a cylinder 2. The piston 1 is provided with three circumferential grooves 3 »4» 5 with a pike-corner cross-section, each of which has a piston ring with an approximately rectangular cross-section 6, 7, 8 records.

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This creates annular spaces e ^, e ₂ , e, and e ^ "on both sides of each piston ring between the piston 1 and the cylinder 2.

The axis A of the cylinder 2 is approximately horizontal. One end 2a of the cylinder is designed as a 1-hour chamber C. More specifically, as shown in Fig. 1, the end 2a is through a partially shown cylinder head completed, in which valves 10 are provided for the inlet and outlet of the gases.

The other end 2b of the cylinder 2 opens into a (not visible) housing for receiving the lubrication the atmosphere causing the engine.

The circumferential grooves 3, 4, 5 follow one another in the sense going from the combustion chamber C to the housing.

The circumferential groove 5 furthest away from the combustion chamber C is provided with the oil control ring 8. This Scraper ring 8 occurs with little play between the flat transverse surfaces 5a, 5p_ of the groove 5 · In the oil scraper ring 8 channels 11 are provided in the usual way to allow the oil stripped from this ring to reach the bottom of the groove 5 can drain. In the bottom of the groove 5 openings 12 are provided in order to connect them to an internal volume D of the piston 1 in To set connection, which is in connection with the housing.

The two grooves that are closer to the chamber C.

3 and 4 take piston rings 6 and 7 with a full rectangular cross-section which are intended to effect the seal between the cylindrical wall of the piston 1 and the cylinder 2. The piston rings 6 and 7 are formed in the usual way by elastic slot rings, which with little play between the flat transverse surfaces 3a, 3 £ l and 4a, 4b of the grooves 3 and

4 kick. The piston rings 6 and 7 are inserted into the cylinder 2 with a slight preload, so that the outer circumferential surface of these rings lies against the surface of the bore of the cylinder 2. The height of entry of the piston rings into the grooves 3 and 4 is in Jj ¹ Ig. 1 represented by h. There is a play J between the bottom of the out and the cylindrical inner surface of the piston rings 6 and 7. The piston ring 6 closest to the chamber G is generally referred to as the "return

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Impact ring "called, while the intermediate ring 7 is the sealing ring forms.

Furthermore, between the oil control ring 8 and the Because of its groove there is a game which is equal to game j.

With each groove 3 »4 different from the groove 5 provided with the oil control ring 8, permeability means M. with a small cross section enable the establishment of a permanent connection between the base of the iiut 3» 4 and the annular spaces e. and e _? in the nut 3 and e _2, and e, wherein the groove 4, which on either side of the groove in question associated piston ring 6, 7 lie · For the groove 5 second passage means M ₂ are provided with small cross-section, a permanent connection of the reason this Create a groove with at least the annular space e ^ which is on the side of the combustion chamber C in relation to the oil control ring.

These first and second passage means AL and M ₂ are higher than the lower zone E of the cylinder, in which liquid lubricant can collect when the engine is stopped.

The first passage means UL comprise for each Grooves 3 and 4 on each flat, transverse surface 3, a »3p_ and 4a, 4b at least one incision labeled 15, 16 (groove 3) or 13, 14 (groove 4).

The second passage means Mp with a small cross section comprise an incision 17 at least on the surface 5a of the groove 5 on the side of the combustion chamber C

Each of these notches (or recesses) 13 to 17 opens out on the outer surface of the piston 1 and extends towards the bottom of the groove over a height which is at least equal to the height h of the introduction of the piston ring in the groove.

These incisions 13 ″ to 17 are preferably above the horizontal one passing through the axis A of the piston Level. The zone of these cuts is practically diametrically opposed to the lower zone E.

The incisions 13 and 14 provided in each transverse surface 4a, 4b of the groove 4 are preferably one another arranged opposite. As shown in Fig. 2, each incision has

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proceeds, a cross section in the form of a segment of a circle. The through the cross-sections of the opposing incisions 13 and 14 formed circle segments are expediently inscribed in the same circumference. The incisions 13 and 14 can therefore be produced directly by a single machining operation, e.g. by means of a drill, the diameter of which is greater than the width of the groove 4. The introduction of the drill into the groove creates one of the cuts 13 and 14 corresponding material removal

The above features are also applicable to the incisions 15 and 16.

The incision 17 also has a cross section in the form of a segment of a circle.

The dimension _1 (Fig. 2) of the incisions in the axis of the cylinder is at most 0.2 mm.

As can be clearly seen from Fig. 2, the incisions of two successive grooves in the transverse direction are d »h. in the circumferential direction of the grooves, against each other offset

The passage means ML and M ₂ according to the invention with a small cross-section enable the reduction and practically the suppression of the cloud of smoke which so far often occurred when starting horizontal engines, especially four-stroke engines whose cylinders have completely closed cylindrical walls.

The invention has practically consisted in finding out that the main cause of this cloud of smoke is the creation of a negative pressure in the combustion chamber C compared to the housing in the. The engine is at a standstill. It has been found that such a negative pressure occurs essentially with a closed combustion chamber C at a standstill during the cooling phase of the engine as a result of the contraction of the volume of gas enclosed in the chamber. This negative pressure can reach such a great value that it sucks oil into the chamber C which has collected in the vicinity of the lower surface line of the cylinder 2 on the side of the housing in the zone E. This phenomenon occurs in particular when the interruption of the piston rings 6 and 7 is in the zone of the lower surface line of the cylinder 2. This interruption, which

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Before the distance between the "two adjacent ends of a piston ring corresponds, there is then a passage for the oil to the combustion chamber C. The passage means M ₁ and M ₂ according to the invention enable a connection to be established between the chamber G and the housing resist the formation of a negative pressure in the combustion chamber with respect to the housing when the engine is at a standstill.

Since no noticeable negative pressure can occur in the combustion chamber G in relation to the housing, the oil will pass through from the housing to the combustion chamber when the engine is stopped is considerably reduced and practically eliminated.

Bs should be noted that the through the various cuts 15, 16, 13t 14 ue * ³ * 17i the annular spaces e, -, e _2> ez in combination with the play between the piston rings and the bottom of the grooves 3, 4- and 5 formed passage forms a labyrinth seal with a small passage cross-section.

This constant passage therefore plays practically no dynamic role in the operation of the engine.

It should also be noted that means can be provided for each piston ring 6, 7 »8 in its groove in a specific To keep angular position. These holding means enable to hold each piston ring at a given angular position relative to the cylinder. In particular, the interruption of the piston rings are held in a zone diametrically opposite the lower zone E.

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Claims (1)

- 8 - 0457 7i? B. PATENT APPROPRIATIONS ^; / 1 · Internal combustion engine with a reciprocating motion piston with at least one piston which slides in a cylinder with an approximately horizontal axis, one end of which forms a combustion chamber, while the other end in a housing to accommodate an atmosphere that lubricates the engine opens, the piston being provided with at least two circumferential grooves, each of which is provided with a piston ring with an approximately rectangular cross-section, so that annular spaces are created on both sides of each piston ring between the piston and the cylinder, the circumferential groove furthest from the combustion chamber with an oil control ring is provided, this groove in its base contains openings which they put in connection with an inner volume of the piston, which in turn is in connection with the housing, characterized in that it has different groove (3 »4) first passage means (M.) with a small cross-section, which establish a permanent connection between the base of the groove and the annular spaces (e ^, e ₂ , e,) on both sides of the piston ring assigned to the groove in question, and second passage means (5) for the groove (5) provided with the oil control ring (8) M ₂ ) with a small cross-section, which connect the bottom of this groove (8) at least with the annular space (e,) which is on the combustion chamber side with respect to the oil control ring, the first and second passage means also being higher lie than the lower zone (E) of the cylinder (2), in which liquid lubricant can collect when the engine is not running. 2. Motor according to claim 1, characterized in that the first passage means (M ₁ ) for each groove (3, 4) and on each transverse surface (3a, 3b, 4a, 4b) of the groove have at least one incision (15, 16; 13, 14), which opens at the outer surface of the piston and extends in the direction of the bottom of the groove over a height which is at least equal to the height (h) of the entry of the piston ring into the groove, while the for _{the second passage means (M 2} ) provided with the oil control ring has at least one incision (17) on the transverse, on the side of the combustion chamber (0) 609817/0782 - 9 - 0457 75 B Include side (5a) of the groove. 3. Motor according to claim 2, characterized in that the first passage means in a transverse Surface of a groove provided notch (13, 15) the notch (14, 16) of the other Querliegeoien surface of the groove suf iciently. 4. Motor according to claim 2 or 3, characterized in that each incision (13, 14, 15, 16, 17) has one Has cross-section in the form of a segment of a circle. 5 · Motor according to claim 3 and 4, characterized in that the circular sections of the opposite Incisions (13, 14, 15, 16) are inscribed in the same circumference. 6. Motor according to claim 2 or claim 2 and one of claims 3 to 5 »characterized in that the incisions (15, 16; 13, 14) of two successive grooves (3, 4) are offset from one another in the transverse direction. 7. Motor according to one of claims 1 to 6, characterized in that the first and the second passage means (M _-1 , Mp) lie approximately diametrically opposite zone in one of the lower surface line of the piston (1). 8. Motor according to claim 4 or claim 4 and one of claims 5 to 7t, characterized in that the largest dimension (1) of each incision in the direction of the axis of the cylinder is at most 0.2 mm. 9. Pistons for internal combustion engines with at least two circumferential grooves with an approximately rectangular cross-section, the The groove in its base furthest from the head of the piston communicates with an internal volume of the piston has setting openings, characterized in that the of The groove (5) furthest from the head of the piston, at least on its transverse groove closest to the head of the piston Surface (5a) is provided with an incision (17), the cross-section of which has in particular the shape of a segment of a circle, while the other or the other grooves (3, 4) closer to the head of the piston on each of their transverse surfaces at least have an incision, the cross section of which is formed in particular by a segment of a circle. 10. Piston according to claim 9 »marked thereby- 609817/0782 ~ 10 - 04-57 75 B net, that the incisions are arranged in such a way that the grooves of the piston at their transversal faces laugh over an angular range, which is greater than 180 °, do not have any incision. 609817/0782